Many have been the hypotheses of the origins of the name, some kept at the start called Crassetum, other Rosetum anchor, but on some papal bubbles of 1138, they clearly indicate the zone with the name of Grossetum. The coat of arms of the city was intentional just from the citizens to demonstration of their descendancys with the antichi Etruschi. The grifone winged, mythical animal already known near the ancient people, placed later on on one meant red shield to of the Ghibelline party.
Later the coat of arms came newly modified adding to grifone in the 1328 one sword in memory of the defense of the city against Lodovico the Bavaro. Between monuments of the city that we want to cite are the strong ones walls of the 1500's, that they have known to resist to the time and to multiple you besiege, the Dome built up between the 1294 and 1302 on the rests of an ancient church of the 1200 and finally church of S. Francisco erected from the Benedictines in XIII the century, it has one gotica facade and to the inside the Cross of Duccio di Buoninsegna of 1289 is still found.